1. Field of the Invention
Gasoline compositions are highly refined products. Despite this, they contain minor amounts of impurities which can promote corrosion during the period that the fuel is transported in bulk or held in storage. Corrosion can also occur in the fuel tank, fuel lines and carburetor of a motor vehicle. As a result, a commercial motor fuel composition must contain a corrosion inhibitor to inhibit or prevent corrosion.
Internal combustion engine design is undergoing changes to meet new standards for engine exhaust gas emissions. One design change involves the feeding of blow-by gases from the crankcase zone of the engine into the intake air supply to the carburetor rather than venting these gases to the atmosphere as in the past. Another change involves recycling part of the exhaust gases to the combustion zone of the engine in order to minimize objectionable emissions. Both the blow-by gases from the crankcase zone and the recycled exhaust gases contain significant amounts of deposit-forming substances which promote the formation of deposits in and around the throttle plate area of the carburetor. These deposits restrict the flow of air through the carburetor at idle and at low speeds so that an overrich fuel mixture results. This condition produces rough engine idling or stalling causing an increase in the amount of polluting exhaust gas emisions, which the engine design changes were intended to overcome, and decreasing fuel efficiency.
Certain N-alkyl-alkylene diamine compounds, as represented by N-oleyl-1,3-diaminopropane, are known to give carburetor detergency properties to gasoline. These additives, however, do not impart corrosion inhibiting properties to gasoline. As a result, a motor fuel containing an N-alkyl-alkylene diamine must be further modified or supplemented with another additive in order to have the necessary corrosion inhibiting properties for marketability.